/* ═══════════════════════════════════════════════
   SceneView — Professional Light Theme
   Google-style: Google Sans Display + Roboto
   ═══════════════════════════════════════════════ */
@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@400;500;700&display=swap');

@font-face {
  font-family: 'Google Sans Display';
  src: url('../font/Google_Sans_Display-Regular.ttf') format('truetype');
  font-weight: 400;
  font-display: swap;
}
@font-face {
  font-family: 'Google Sans Display';
  src: url('../font/Google_Sans_Display-Medium.ttf') format('truetype');
  font-weight: 500;
  font-display: swap;
}
@font-face {
  font-family: 'Google Sans Display';
  src: url('../font/Google_Sans_Display-Bold.ttf') format('truetype');
  font-weight: 700;
  font-display: swap;
}

/* ── Reset & Base ─────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:          #ffffff;
  --bg-soft:     #f8f9fa;
  --bg-muted:    #f1f3f4;
  --surface:     #ffffff;
  --border:      #dadce0;
  --border-light:#e8eaed;

  --text:        #202124;
  --text-secondary: #5f6368;
  --text-muted:  #80868b;

  --accent:      #1a73e8;
  --accent-soft: #e8f0fe;
  --accent-hover:#1765cc;
  --accent-text: #ffffff;

  --green:       #1e8e3e;
  --green-soft:  #e6f4ea;
  --cyan:        #129eaf;
  --cyan-soft:   #e4f7fb;

  --font-sans:   'Roboto', system-ui, -apple-system, 'Segoe UI', sans-serif;
  --font-head:   'Google Sans Display', 'Roboto', system-ui, sans-serif;
  --font-mono:   'Roboto Mono', 'Fira Code', ui-monospace, monospace;

  --section-gap: clamp(3.5rem, 8vw, 5.5rem);
  --container:   1140px;
  --radius:      8px;
  --radius-lg:   12px;
  --radius-xl:   16px;

  --shadow-sm:   0 1px 2px 0 rgba(60,64,67,0.1);
  --shadow:      0 1px 2px 0 rgba(60,64,67,0.3), 0 1px 3px 1px rgba(60,64,67,0.15);
  --shadow-md:   0 1px 3px 0 rgba(60,64,67,0.3), 0 4px 8px 3px rgba(60,64,67,0.15);
  --shadow-lg:   0 4px 8px 3px rgba(60,64,67,0.15), 0 1px 3px rgba(60,64,67,0.3);

  --ease:        cubic-bezier(0.4, 0, 0.2, 1);
}

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--bg-muted);
  padding: 2px 6px;
  border-radius: 4px;
}

h1, h2, h3, h4 {
  font-family: var(--font-head);
  font-weight: 500;
  line-height: 1.25;
  letter-spacing: -0.01em;
  color: var(--text);
}


/* ── Gradient text ────────────────────────────── */
.text-gradient {
  background: linear-gradient(135deg, var(--accent) 0%, #34a853 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}


/* ── Layout ───────────────────────────────────── */
.section {
  padding: var(--section-gap) 0;
  max-width: var(--container);
  margin: 0 auto;
  padding-left: clamp(1.5rem, 4vw, 3rem);
  padding-right: clamp(1.5rem, 4vw, 3rem);
}

.section__header { text-align: center; margin-bottom: 2.5rem; }

.section__label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-head);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.625rem;
}

.section__label::before {
  content: '';
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--accent);
}

.section__title {
  font-size: clamp(1.625rem, 3.5vw, 2.25rem);
  font-weight: 500;
  margin-bottom: 0.625rem;
}

.section__subtitle {
  font-size: 1rem;
  color: var(--text-secondary);
  max-width: 560px;
  margin: 0 auto;
  line-height: 1.65;
}


/* ── Grids ────────────────────────────────────── */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.25rem; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.25rem; }

@media (max-width: 900px) { .grid-3 { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 600px) {
  .grid-2 { grid-template-columns: 1fr; }
  .grid-3 { grid-template-columns: 1fr; }
}


/* ── Nav ──────────────────────────────────────── */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0.75rem clamp(1.5rem, 4vw, 3rem);
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-light);
}

.nav__logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-head);
  font-weight: 500;
  font-size: 1.0625rem;
  color: var(--text);
  flex-shrink: 0;
}
.nav__logo img { width: 28px; height: 28px; border-radius: 6px; }

.nav__links {
  display: flex;
  list-style: none;
  gap: 0;
  margin-left: auto;
}
.nav__links a {
  display: block;
  padding: 0.4375rem 0.75rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: var(--radius);
  transition: color 0.15s var(--ease), background 0.15s var(--ease);
}
.nav__links a:hover { color: var(--text); background: var(--bg-muted); }
.nav__links a.active { color: var(--accent); background: var(--accent-soft); }

.nav__github {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 0.4375rem 0.875rem;
  margin-left: 0.25rem;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--bg-muted);
  border-radius: var(--radius);
  transition: background 0.15s var(--ease);
  flex-shrink: 0;
}
.nav__github:hover { background: var(--border); }

.nav__menu-btn {
  display: none;
  background: none;
  border: none;
  padding: 0.4375rem;
  cursor: pointer;
  color: var(--text);
  border-radius: var(--radius);
  margin-left: auto;
}
.nav__menu-btn:hover { background: var(--bg-muted); }

.nav__mobile {
  display: none;
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  z-index: 99;
  background: var(--bg);
  padding: 4.5rem 1.5rem 1.5rem;
  flex-direction: column;
  gap: 0.125rem;
}
.nav__mobile.open { display: flex; }
.nav__mobile a {
  display: block;
  padding: 0.875rem 1rem;
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: var(--radius-lg);
  transition: background 0.15s var(--ease);
}
.nav__mobile a:hover { background: var(--bg-muted); }
.nav__mobile a.active { color: var(--accent); background: var(--accent-soft); }

@media (max-width: 768px) {
  .nav__links { display: none; }
  .nav__github { display: none; }
  .nav__menu-btn { display: block; }
}


/* ── Buttons ──────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 0.625rem 1.375rem;
  font-family: var(--font-head);
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: var(--radius);
  border: none;
  cursor: pointer;
  transition: all 0.15s var(--ease);
  white-space: nowrap;
  letter-spacing: 0.01em;
}

.btn--primary {
  background: var(--accent);
  color: var(--accent-text);
  box-shadow: var(--shadow-sm);
}
.btn--primary:hover {
  background: var(--accent-hover);
  box-shadow: var(--shadow);
}

.btn--outline {
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
}
.btn--outline:hover { background: var(--bg-soft); }

.btn--sm { padding: 0.4375rem 0.875rem; font-size: 0.8125rem; }


/* ── Tags ─────────────────────────────────────── */
.tag {
  display: inline-block;
  padding: 2px 8px;
  font-size: 0.6875rem;
  font-weight: 500;
  border-radius: 4px;
  background: var(--bg-muted);
  color: var(--text-secondary);
  letter-spacing: 0.01em;
}
.tag--accent { background: var(--accent-soft); color: var(--accent); }
.tag--cyan { background: var(--cyan-soft); color: var(--cyan); }
.tag--green { background: var(--green-soft); color: var(--green); }


/* ── Hero ─────────────────────────────────────── */
.hero {
  text-align: center;
  padding: clamp(3.5rem, 10vw, 7rem) clamp(1.5rem, 4vw, 3rem) clamp(2.5rem, 6vw, 4rem);
  max-width: 780px;
  margin: 0 auto;
}

.hero__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 14px 5px 8px;
  font-family: var(--font-head);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--accent);
  background: var(--accent-soft);
  border-radius: 100px;
  margin-bottom: 1.75rem;
}
.hero__eyebrow-dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--accent);
  animation: pulse 2s ease-in-out infinite;
}
@keyframes pulse { 0%, 100% { opacity: 1; } 50% { opacity: 0.3; } }

.hero__title {
  font-size: clamp(2rem, 5.5vw, 3.25rem);
  font-weight: 500;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 1.25rem;
}

.hero__desc {
  font-size: clamp(0.9375rem, 1.8vw, 1.0625rem);
  color: var(--text-secondary);
  line-height: 1.65;
  max-width: 520px;
  margin: 0 auto 2rem;
}

.hero__ctas {
  display: flex;
  gap: 0.625rem;
  justify-content: center;
  flex-wrap: wrap;
}


/* ── Stats ────────────────────────────────────── */
.stats-strip {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.75rem;
  padding: 1.5rem 0;
}
.stat-item {
  text-align: center;
  padding: 1.25rem 0.75rem;
  background: var(--bg-soft);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
}
.stat-item__value {
  display: block;
  font-family: var(--font-head);
  font-size: clamp(1.5rem, 3.5vw, 2rem);
  font-weight: 500;
  color: var(--accent);
  line-height: 1.2;
}
.stat-item__label {
  display: block;
  font-size: 0.8125rem;
  font-weight: 400;
  color: var(--text-muted);
  margin-top: 0.125rem;
}
@media (max-width: 600px) { .stats-strip { grid-template-columns: repeat(2, 1fr); } }


/* ── Cards ────────────────────────────────────── */
.card {
  background: var(--surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  transition: border-color 0.15s var(--ease), box-shadow 0.15s var(--ease);
}
.card:hover { border-color: var(--border); box-shadow: var(--shadow-md); }
.card__icon { font-size: 1.5rem; margin-bottom: 0.875rem; line-height: 1; }
.card__title {
  font-family: var(--font-head);
  font-weight: 500;
  font-size: 1rem;
  margin-bottom: 0.375rem;
}
.card__body {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.6;
  flex: 1;
}
.card__link {
  display: inline-flex;
  align-items: center;
  gap: 3px;
  margin-top: 1rem;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--accent);
  transition: gap 0.15s var(--ease);
}
.card__link:hover { gap: 6px; }


/* ── Repo Cards ───────────────────────────────── */
.repo-card {
  display: flex;
  flex-direction: column;
  background: var(--surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  transition: border-color 0.15s var(--ease), box-shadow 0.15s var(--ease);
}
.repo-card:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-md);
}
.repo-card__logo { width: 40px; height: 40px; border-radius: 10px; margin-bottom: 1rem; object-fit: contain; }
.repo-card__name { font-family: var(--font-head); font-weight: 500; font-size: 1.0625rem; margin-bottom: 0.375rem; }
.repo-card__desc { font-size: 0.875rem; color: var(--text-secondary); line-height: 1.6; flex: 1; margin-bottom: 0.875rem; }
.repo-card__tags { display: flex; gap: 5px; flex-wrap: wrap; margin-bottom: 1rem; }


/* ── Sponsors ─────────────────────────────────── */
.sponsors-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1rem;
  padding: 0.75rem 0;
}
.sponsor-item {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 128px;
  height: 64px;
  padding: 0.875rem;
  background: var(--bg-soft);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  transition: border-color 0.15s var(--ease), box-shadow 0.15s var(--ease);
}
.sponsor-item:hover { border-color: var(--border); box-shadow: var(--shadow); }
.sponsor-item img {
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
  filter: grayscale(100%) opacity(0.5);
  transition: filter 0.15s var(--ease);
}
.sponsor-item:hover img { filter: grayscale(0%) opacity(1); }


/* ── Page Hero (subpages) ─────────────────────── */
.page-hero {
  text-align: center;
  padding: clamp(2.5rem, 6vw, 4rem) clamp(1.5rem, 4vw, 3rem) clamp(1.5rem, 3vw, 2.5rem);
  max-width: 660px;
  margin: 0 auto;
}
.page-hero__title { font-size: clamp(1.75rem, 4.5vw, 2.5rem); font-weight: 500; letter-spacing: -0.02em; margin-bottom: 0.75rem; }
.page-hero__subtitle { font-size: 1rem; color: var(--text-secondary); line-height: 1.65; max-width: 520px; margin: 0 auto; }


/* ── Feature Items ────────────────────────────── */
.feature-item {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
  align-items: center;
  padding: 2.5rem 0;
  border-bottom: 1px solid var(--border-light);
}
.feature-item:last-child { border-bottom: none; }
.feature-item:nth-child(even) .feature-item__media { order: -1; }

.feature-item__badge {
  display: inline-block;
  padding: 3px 10px;
  font-family: var(--font-head);
  font-size: 0.6875rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  border-radius: 4px;
  background: var(--accent-soft);
  color: var(--accent);
  margin-bottom: 0.75rem;
}
.feature-item__title { font-size: 1.375rem; font-weight: 500; letter-spacing: -0.01em; margin-bottom: 0.625rem; }
.feature-item__desc { font-size: 0.875rem; color: var(--text-secondary); line-height: 1.65; }

.feature-item__media {
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-sm);
}
.feature-item__media img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

@media (max-width: 768px) {
  .feature-item { grid-template-columns: 1fr; gap: 1.25rem; }
  .feature-item:nth-child(even) .feature-item__media { order: 0; }
}


/* ── API Cards ────────────────────────────────── */
.api-card {
  display: flex;
  flex-direction: column;
  gap: 0.875rem;
  background: var(--surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  transition: border-color 0.15s var(--ease), box-shadow 0.15s var(--ease);
}
.api-card:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-md);
}
.api-card__title { font-family: var(--font-mono); font-weight: 500; font-size: 1.0625rem; }
.api-card__desc { font-size: 0.875rem; color: var(--text-secondary); line-height: 1.6; }


/* ── Contribute Blocks ────────────────────────── */
.contribute-block {
  display: flex;
  flex-direction: column;
  gap: 0.625rem;
  background: var(--surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  transition: border-color 0.15s var(--ease), box-shadow 0.15s var(--ease);
}
.contribute-block:hover { border-color: var(--border); box-shadow: var(--shadow-md); }
.contribute-block__title { font-family: var(--font-head); font-size: 1.125rem; font-weight: 500; }
.contribute-block__body { font-size: 0.875rem; color: var(--text-secondary); line-height: 1.65; }


/* ── CTA Band ─────────────────────────────────── */
.cta-band {
  background: var(--bg-soft);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-xl);
  padding: clamp(2rem, 4vw, 3.5rem);
  text-align: center;
}
.cta-band__title { font-size: clamp(1.375rem, 3.5vw, 2rem); font-weight: 500; letter-spacing: -0.02em; margin-bottom: 0.75rem; }
.cta-band__desc { color: var(--text-secondary); font-size: 0.9375rem; max-width: 440px; margin: 0 auto 1.5rem; line-height: 1.6; }
.cta-band__actions { display: flex; gap: 0.625rem; justify-content: center; flex-wrap: wrap; }


/* ── Info Box ─────────────────────────────────── */
.info-box {
  padding: 1.5rem;
  background: var(--accent-soft);
  border: 1px solid rgba(26,115,232,0.15);
  border-radius: var(--radius-lg);
}


/* ── Footer ───────────────────────────────────── */
.footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  max-width: var(--container);
  margin: 0 auto;
  padding: 1.75rem clamp(1.5rem, 4vw, 3rem);
  border-top: 1px solid var(--border-light);
  flex-wrap: wrap;
}
.footer__left {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.875rem;
  font-weight: 500;
  font-family: var(--font-head);
}
.footer__left img { width: 22px; height: 22px; border-radius: 5px; }
.footer__copy { font-family: var(--font-sans); font-weight: 400; color: var(--text-muted); font-size: 0.8125rem; }
.footer__links { display: flex; align-items: center; gap: 1rem; }
.footer__links a {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: color 0.15s var(--ease);
}
.footer__links a:hover { color: var(--text); }
.social-icon { width: 16px; height: 16px; }


/* ── Scroll Reveal ────────────────────────────── */
.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.4s var(--ease), transform 0.4s var(--ease);
}
.reveal.visible { opacity: 1; transform: translateY(0); }